The present invention relates in general to materials handling vehicles and, more particularly, to an improved operator's station including a three position seat for use in such vehicles which permits operators of the vehicles to stand, perch or sit while maintaining the eyes of the operators at substantially the same vertical level regardless of the operators' positions. While the present invention is generally applicable to materials handling vehicles, it is described herein with reference to a fork lift truck, specifically a rider reach truck, for which it is particularly applicable and initially being used.
To best ensure efficient operation of a fork lift truck, such as a rider reach truck, during the time encompassed by a normal length operating shift, it is desirable that the operator be comfortable throughout the shift. Operator comfort can depend upon being able to operate the truck in a desired position, such as standing, sitting or perching, depending upon the operator's preference and the application. Also, due to the time extent of a normal operating shift, operators may want to change their operating position since a single operating position may, depending upon an application and use of the truck, become less comfortable over time even when an operator is able to move or shift within that position. Accordingly, provisions have been made to provide alternate operating positions for fork lift trucks. For example, in U.S. Pat. No. 5,275,255, an integrated controls and seating arrangement is disclosed for reach fork vehicles.
In the '255 patent, an operator's station includes a seat which is movable between a lowered position and a raised position. A seated operating position is provided when the seat is lowered and, when the seat is raised, standing and/or leaning positions are provided. In the leaning position, an operator leans against the raised seat. Pivoting control arms are also provided. As described, the arms are pivoted to a down position for the seated and leaning positions and to an upright position for the standing position. While alternate operating positions are thus provided, sitting on or leaning against the top of a folded seat is not an ideal comfortable alternate operating position. Further, it is apparent that the eyes of the operator are located at differing vertical levels depending upon the operating position which is selected by the operator. Such different vertical levels for the operator's eyes produce different perspective views for the operator which may impact operation of the vehicle and the efficiency of the operator.
There is, thus, a need for an improved operator's station for materials handling vehicles to provide a number of alternate operating positions which are comfortable for operators of the vehicles. Preferably, the improved operator's station would include a seat which would not only provide comfortable alternate operating positions but also would maintain the eyes of operators at substantially the same vertical level regardless of the operating position selected by the operator to thereby further improve consistent and efficient operation of the vehicles.